package xzy.com.config.jwt.interceptor;

import java.lang.reflect.Method;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.exceptions.JWTVerificationException;

import xzy.com.config.jwt.annotation.PassToken;
import xzy.com.config.jwt.annotation.UserLoginToken;
import xzy.com.entity.domain.Users;
import xzy.com.service.UserService;
import xzy.com.util.JwtUtil;

/**
 * 拦截前端请求，获取token并验证token
 * 主要流程:
1.从 http 请求头中取出 token，
2.判断是否映射到方法
3.检查是否有passtoken注释，有则跳过认证
4.检查有没有需要用户登录的注解，有则需要取出并验证
5.认证通过则可以访问，不通过会报相关错误信息
 */
public class AuthenticationInterceptor implements HandlerInterceptor {
    @Autowired
    UserService userService;
    /**
    主要流程：
    1.从 http 请求头中取出 token，
	2.判断是否映射到方法
	3.检查是否有passtoken注释，有则跳过认证
	4.检查有没有需要用户登录的注解，有则需要取出并验证
	5.认证通过则可以访问，不通过会报相关错误信息
     * */
    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object object) throws Exception {
    	System.out.println("拦截前端请求，获取并验证token");
    	// 从 http 请求头中取出 token
    	String token = httpServletRequest.getHeader("Authorization");
        // 如果不是映射到方法直接通过
        if(!(object instanceof HandlerMethod)){
            return true;
        }
        HandlerMethod handlerMethod=(HandlerMethod)object;
        Method method=handlerMethod.getMethod();
        //检查是否有passtoken注释，有则跳过认证
        if (method.isAnnotationPresent(PassToken.class)) {
            PassToken passToken = method.getAnnotation(PassToken.class);
            if (passToken.required()) {
                return true;
            }
        }
        //检查有没有需要用户权限的注解
        if (method.isAnnotationPresent(UserLoginToken.class)) {
            UserLoginToken userLoginToken = method.getAnnotation(UserLoginToken.class);
            if (userLoginToken.required()) {
                // 执行认证
                if (token == null) {
                    throw new RuntimeException("无token，请重新登录");
                }
                // 获取 token 中的 user id
                String userId;
                try {
                    //userId = JWT.decode(token).getAudience().get(0);
                	userId=JwtUtil.getClaim(token,"account");
                	//userId = JWT.decode(token).getClaims().get("account").asString();
                } catch (JWTDecodeException j) {
                    throw new RuntimeException("401");
                }
                Users user = userService.getByName(userId);
                if (user == null) {
                    throw new RuntimeException("用户不存在，请重新登录");
                }
                // 验证 token
                //JWTVerifier jwtVerifier = JWT.require(Algorithm.HMAC256(user.getPwd())).build();
                try {
                	// 验证 token
                	JwtUtil.verify(token);
                	return true;                	
                    //jwtVerifier.verify(token);
                } catch (JWTVerificationException e) {
                    throw new RuntimeException("401");
                }                
            }
        }
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {

    }
    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {

    }
}
